Model airplane

ABSTRACT

A model airplane having a pivotable wing for imparting superior aerodynamic performance characteristics. Wings are folded toward fuselage during airplane launch and automatically extended outwardly during flight to provide airplane lift surfaces for a gliding descent.

ited States Patent lmperato [151 3,654,729 [451 Apr. 11, 1972 [54] MODEL AIRPLANE [72] Inventor: Joseph lmperato, Selden, NY.

[73] Assignee: Sport Games, Inc., Great Neck, N.Y.

[22] Filed: Sept. 12, 1969 [2]] Appl. No.: 862,626

[52] US. Cl ..46/80 [51] lnt.Cl...... [58] FieldofSearch [56] References Cited UNITED STATES PATENTS 3,006,109 10/1961 Boese ..46/80 Primary Examiner-Russell R. Kinsey Assistant Examiner-J. Q. Lever Attorney-Edward H. Loveman [5 7] ABSTRACT A model airplane having a pivotable wing for imparting superior aerodynamic performance characteristics. Wings are folded toward fuselage during airplane launch and automatically extended outwardly during flight to provide airplane lift surfaces for a gliding descent.

3 Claims, 9 Drawing Figures PATENTEDAPR 1 1 I972 SHEET 1 [IF 2 INVEN TOR JOSEPH IMPERATO rmmvrv PATENTEDAPR 1 1 I972 SHEET 2 or 2 INVENTOR JOSEPH IMPERATO ATTORNEY MODEL AIRPLANE This invention relates to model airplanes or the like and, more particularly, to a novel and unique model airplane having foldable wings adapted to impart improved flying performance characteristics to the airplane.

Model airplanes are widely known and enjoyed by numerous adolescents and adults throughout the world for sport and recreational purposes. These airplanes may range from the simplest and most inexpensive constructions to the most highly sophisticated and costly machines. Materials and propulsive devices for the model airplanes also extend through a considerable range, designed to impart the best possible flying and operating characteristics to the model planes. One important aspect of model airplane construction lies in the configuration or aerodynamic shape of the airplane fuselages and wings. When properly designed, from an aerodynamic viewpoint, even a relatively simple and inexpensive model airplane can achieve a high degree of flying proficiency. This will, in effect, greatly enhance the the enjoyment by the person owning or using the model airplane. The shape of the model airplane wings are of particular significance in determining the aerodynamic or flight performance characteristics of the airplane. Prior art model airplanes employ a fixed or stationary wing construction, that is, a pair of wings which are rigidly mounted on a fuselage section. Although these fixed wing" model airplanes may present a generally satisfactory performance during flight, the wing construction frequently hinders or retards the launching operation of model airplane. Thus, for example, during initial launching of the airplane into flight, the extending wings may present a drag or wind resistance which may prevent the fixed wing model airplane from reaching its full flying potential and performance. Furthermore, during the launching of prior art model airplanes there is also the danger of damaging the generally fragile extending wings when imparting the initially high accelerations to the airplanes.

The model airplane according to the present invention obviates and overcomes the drawbacks and shortcomings encountered in prior art model airplanes by providing a model airplane which incorporates a novel and unique pivotable wing construction adapted to enhance the aerodynamic performance characteristics of the airplane. For this purpose, the present invention contemplates a pivoted or folding wing construction whereby the airplane wings are retained against the airplane fuselage in flat folded position during initial launch so as to reduce initial air drag on the airplane. During flight, upon the model airplane reaching a predetermined accelerating condition or attitude, the wings extend under the urging of resilient tension devices, so as to impart the desired flight or aerodynamic performance characteristics to the model airplane. This, in effect, will add greatly to the enjoyment of using and flying the model airplane.

Accordingly, it is a primary object of the present invention to provide an improved and novel model airplane.

Another object of the present invention is to provide a novel model airplane having pivotally mounted foldable wings adapted to enhance the aerodynamic performance characteristics of the airplane.

Yet another object of the present invention is to provide a novel model airplane having a foldable wing construction adapted to be folded during airplane launch and to be extendable upon the airplane reaching a predetermined flight performance attitude.

These and other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, in which:

FIG. 1 is a top plan view of a model airplane according to the present invention;

FIG. 2 is a side elevational view of the model airplane illustrated in FIG. 1;

FIG. 3 is an elevational sectional view along line 33 in FIG. 1;

FIG. 4 is a sectional view along line 4-4 in FIG. 1, showing the airplane wings in extended position;

FIG. 5 is a sectional view along line 5-5 in FIG. 1;

FIG. 6 is a view of the model airplane according to the present invention, in the process of being launched;

FIG. 7 is a sectional view along line 77 in FIG. 1;

FIG. 8 is a sectional view along line 8-8 in FIG. 2; and

FIG. 9 is a sectional view along line 9--9 in FIG. 1.

Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is illustrated a model airplane generally designated as reference numeral 10. The airplane 10 includes a fuselage section 12, and a pair of Wings 14 and 16. As is well known in the model airplane art, the fuselage and wings may be formed of various types of lightweight materials such as balsa wood, plastic or fabric covered support structure.

As shown, the fuselage section 12 is generally elongate and flat, having a somewhat thickened forward portion 18 which extends into a knife-edged nose or tip 20. The tail end 22 of the fuselage 12 is rectangular and includes a square or rectangular cut-out portion 24. As illustrated in FIGS. 4 and 5, the central portion of the fuselage section 12 has slots or grooves 24 and 26 cut into the sides thereof. The grooves 24, 26 are deeper toward the forward portion of the fuselage 12 and are arcuately curved as shown at 28 and 30 (FIG. 1).

The pair of airplane wings 14 and 16 are mounted onto the fuselage section 12, so that the inner curved wing ends 34 and 36 extend into the grooves 24, 26 in alignment with the curved groove portions 28, 30. The wings are attached to the fuselage 12 by means of pins or dowels 38 which extend through the wings and into the fuselage. The dowels 38 are rigidly positioned in the fuselage 12, whereas the wings have apertures 38a larger than the diameters of the dowels 38. This, in effect, permits the wings to pivot about the dowels so as to be either in fully extended position relative to the fuselage 12, as shown in FIG. 1 in solid lines, or to be folded against the fuselage, as illustrated by the chain-dotted lines.

Each of the wings 14, 16 is attached at its leading edge 40 to a resilient tension cord or rubber band 42, 44 which terminate at connecting loops 46 at the forward portion of fuselage 12, so as to exert a force on the wings, tending to normally move them into an extended position with respect to fuselage 12.

A shaft 48 extends across and is rotatably mounted within the cut-out position 24 of fuselage tail end 22. The center portion of shaft 48 is rigidly coupled to a flat plate or blade 50, which is adapted to be gripped for manual rotation of shaft 48. The blade 50 may be manufactured of thin plastic or rubber which will bend so that the ends thereof will pass through cutout portion 24 when blade 50 is rotated in a manner to be described below. A pair of strings 52 and 54 are wound about the shaft 48 on each side of blade 50. The free end portions of the strings 52, 54 extend respectively through apertures 56 and 58 in the tail portion 22 of fuselage section 12, and are formed into loops or rings 60 and 62. The rings 60, 62 are adapted to be connected to or slid over hook members 64 on the trailing edges 66 of wings 14, 16.

As illustrated in FIGS. 7, 8 and 9, the various airplane portions, such as the wing cross-sections, the tail wings 68 and the stabilizer 70, are shaped to present optimum aerodynamic configurations.

In order launch the airplane 10, as illustrated in FIG. 6 of the drawings, the rings 60 of strings 52, 54 are attached to books 64 on the wings 14, 16. The plate 50 is then manually rotated so as to wind the Strings 52, 54 about shaft 48, thereby folding the wings back against fuselage 12. This, in effect, will stretch the tension cords 42, 44, which are prevented from swinging the wings outwardly by manual gripping of plate 50. As the operator grips the tail end 22 of fuselage and plate 50 with one hand, he attaches a resilient launching device such as a rubber band to a hook 72 adjacent to and below the front end portion 18 of the fuselage section 12.

When sufficient tension on the airplane 10 is attained by the launching device, the operator releases the tail end 22 and plate 50, thereby permitting the launching device to propel the airplane upwards in the form of a projectile. During the time that the airplane is accelerating or in a projectile attitude, gravitational forces will keep the wings folded back against the fuselage l2 notwithstanding the opposing wing-extending forces exerted by resilient tension cords 42, 44.

As the forward acceleration of the airplane decreases, the forces exerted by tension cords 42, 44 exceed the gravitational forces on the wings 14, 16 and the latter are slowly extended outwardly of the fuselage section 12 so as to form lift surfaces for the airplane 10. During the extending movement of the wings, the strings 52, 54 are unwound from shaft 48 and pulled through apertures 56, 58 in the fuselage as the ends of the blade 50 pass through cut-out portions 24. Contact of the strings with the aperture walls together with the rotating of blade 50 will provide some degree of friction to thereby slow down the outward or extending motion of the wings. At some point during the outward motion of the wings, the rings 60, 62 will slide off hooks 64, and the wing 14, 16 will suddenly snap out into their fully extended positions by the force of the tension cords 42, 44. This will create a generally smooth transition in flight of the aircraft from a projectile to that of a glider.

In essence, the aforedescribed model airplane construction clearly provides an airplane of simple and inexpensive design having superior flight performance characteristics.

The foregoing disclosure relates to only a preferred embodiment of the invention, and is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of disclosure, which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

l. A model airplane comprising;

an elongate fuselage section,

a pair of wing members foldably connected to opposite sides of said fuselage section adjacent the forward portion thereof, said wing members being pivotal relative to said fuselage section so as to alternatively radially extend from or fold flat against said fuselage section,

resilient means for nonnally biasing said wing members into said radially extended position,

the tail end portion of said fuselage portion having a cut out portion wing retracting means comprising a shaft rotatably journaled in said cut-out portion of said fuselage section for retracting said wing members into said flat folded position, said wing retracting means being releaseably connected to said wing members whereby said resilient means are adapted to radially extend said wing members during predetermined flight attitudes of said airplane, and

a pair of string members extending from said fuselage section, said string members being adapted to be wound about said shaft, the end portions of said string members being releaseably connected to said wing members so as to maintain the latter in flat folded position when said string members are wound about said shaft.

2. An airplane as defined in claim 1 wherein the end portions of said string members adapted for connection to said wing members include loop means,

said wing members including hook means on their trailing edges adapted to be engaged by said loop means.

3. An airplane as defined in claim 2 wherein said rotatable shaft includes a blade, said blade being manually rotatable so as to facilitate winding of said string members about said shaft, whereby said wing members are folded flat against said fuselage section in opposition to the wing expansive force exerted by said resilient biasing means. 

1. A model airplane comprising; an elongate fuselage section, a pair of wing members foldably connected to opposite sides of said fuselage section adjacent the forward portion thereof, said wing members being pivotal relative to said fuselage section so as to alternatively radially extend from or fold flat against said fuselage section, resilient means for normally biasing said wing members into said radially extended position, the tail end portion of said fuselage portion having a cut out portion wing retracting means comprising a shaft rotatably journaled in said cut-out portion of said fuselage section for retracting said wing members into said flat folded position, said wing retracting means being releaseably connected to said wing members whereby said resilient means are adapted to radially extend said wing members during predetermined flight attitudes of said airplane, and a pair of string members extending from said fuselage section, said string members being adapted to be wound about said shaft, the end portions of said striNg members being releaseably connected to said wing members so as to maintain the latter in flat folded position when said string members are wound about said shaft.
 2. An airplane as defined in claim 1 wherein the end portions of said string members adapted for connection to said wing members include loop means, said wing members including hook means on their trailing edges adapted to be engaged by said loop means.
 3. An airplane as defined in claim 2 wherein said rotatable shaft includes a blade, said blade being manually rotatable so as to facilitate winding of said string members about said shaft, whereby said wing members are folded flat against said fuselage section in opposition to the wing expansive force exerted by said resilient biasing means. 